Timepiece dial



July 22, 1952 c. STERN 2,604,418

TIMEPIECE DIAL Filed Feb. 17, 1948 FIG.!

FIG. 2

FIG 4 k K W FIG. 5 n

4 Mar/4 f v Patented July 22, 1952 UNITED STATES PATENT OFFICE TIMEPIECEDIAL Charles Stern, Geneva, Switzerland Application February 17, 1948,Serial No. 8,839 In Switzerland February 18, 1947 1 Claim. 1

The present invention relates to time-piece dials and has particularreference to a process of manufacturing time-piece dials havingprominent indicia members stamped therefrom.

It is an object of the invention to provide timepiece dials of basemetal or alloys having prominent indicia members stamped therefrom anddurably colored in a color different from that of the dial plate itself.

According to an important feature of the invention prominent indiciamembers are stamped from a plate of light metal or alloy such, forexample, as aluminum or magnesium or their alloys, andthe whole plate issubjected to an oxidizing treatment, preferably to anodic oxidation; theplate is then covered by a layer of commonly known masking material,leaving the prominent indicia members uncovered, then immersed in a dyebath and the masking material removed after dyeing, whereby theprominent indicia members are durably colored in a color different fromthat of the plate from which they are stamped.

The accompanying drawing illustrates the various steps of the invention.

Fig. 1 is a plan view of a watch dial embodying the invention;

The Figures 2 to are enlarged sectional views taken on line A-A of Fig.1 showing a portion of the dial after various steps of the manufacturingprocess.

In carrying out the process, I stamp prominent indicia members, forinstance hour characters as 2, from a plate I made of light metal oralloy such as aluminum, magnesium, aluminum alloy or magnesium alloy; Ithen submit the plate to an oxidizing treatment, either chemically orelectro-chemically, preferably to anodic oxidation, whereby the wholeupper surface of the plate including the faces of the prominent indiciamembers is provided with a layer 3 of aluminum or magnesium oxide, asshown in Fig. 3. The next step is to cover or save the upper surface ofthe plate by a layer 4 of masking material such as cellulosic varnishwhich leaves uncovered the surfaces 5 of the indicia members 2.

The next step is to dye the oxidized surfaces 5 of the indicia members,as by immersion of the dial in a, hot dye bath, and then to remove themasking material 4 as by immersion of the dial in a suitable solvent.

A dial is thus obtained having prominent hour characters or otherindicia members, the upper surface of which is durably colored, forinstance in blue, red or yellow, and thus more neatly 2 stands out inrelief on the background of the dial which may be for example white,shining or of dull satin finish.

Optionally, after oxidation and masking of the plate, the prominentindicia members may be uncovered and polished by means of abrasivematerial, then oxidized and dyed.

Optionally also, the prominent indicia members may be polished andmasked before the oxidizing treatment and the background of the dialgiven a satin finish by well known process; then, after removal of themasking material from the indicia members, the whole may be oxidized,the background masked and the indicia members dyed as hereinbeforedescribed.

What I claim is:

A process for manufacturing time-piece dials comprising the steps ofstamping prominent indicia members from a plate of light metal of thegroup consisting of aluminum, magnesium and alloys of said metalspolishing the prominent indicia members and covering them with maskingmaterial, giving the background of the plate a satin finish, removingthe masking material from the indicia members, oxidizing the whole platetogether with the prominent indicia members, protecting the backgroundof the plate by covering it by a layer of masking material leaving theprominent indicia members uncovered, dyeing the uncovered indiciamembers and removing the masking material from the background.

CHARLES STERN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 430,424 Eaton June 17, 1890864,467 Ingraham Aug. 27, 1907 1,304,749 Divine Ma 27, 1919 1,821,561McFarland Sept. 1, 1931 2,516,986 Heinse Aug, 1, 1950 FOREIGN PATENTSNumber Country Date 445,242 Great Britain Apr. 6, 1936 483,776 GreatBritain Apr. 26, 1938 65,167 Switzerland Mar. 4, 1913 OTHER REFERENCESV. F. Henley, The Metal Industry (London), June 18, 1943, page 388.

